Zobrazeno 1 - 10
of 335
pro vyhledávání: '"A. Mallama"'
Observed magnitudes of Qianfan spacecraft range from 4 when they are near zenith to 8 when low in the sky. Nearly all of the observations can be modeled with a nadir-facing flat antenna panel and the underside of a zenith-facing solar array, both wit
Externí odkaz:
http://arxiv.org/abs/2409.20432
Autor:
Mallama, Anthony, Cole, Richard E., Harrington, Scott, Worley, Aaron, Respler, Jay, Bassa, Cees, Tilley, Scott
The BlueWalker 3 satellite is now fainter than during the first months after deployment. The greatest improvement is that the average maximum luminosity near zenith has been reduced from magnitude 1.0 to 2.2. However, the spacecraft is still usually
Externí odkaz:
http://arxiv.org/abs/2407.04140
The mean apparent magnitude of Starlink Mini Direct-To-Cell (DTC) satellites is 4.62 while the mean of magnitudes adjusted to a uniform distance of 1000 km is 5.50. DTCs average 4.9 times brighter than other Starlink Mini spacecraft at a common dista
Externí odkaz:
http://arxiv.org/abs/2407.03092
Autor:
Mallama, Anthony
SpaceX recently proposed to orbit 19,440 Starlink internet satellites at a low altitude of 350 km instead of the current 550 km. The distribution in the sky and the apparent magnitudes of these spacecraft are simulated in this paper. During astronomi
Externí odkaz:
http://arxiv.org/abs/2406.16589
Autor:
Mallama, Anthony, Cole, Richard E.
Starlink satellites can become extremely bright when sunlight reflects specularly to an observer on the ground. The observed brightness of such flares is consistent with a bidirectional reflectance function of the Starlink satellite chassis. These fi
Externí odkaz:
http://arxiv.org/abs/2405.13091
Observations of Starlink V2 Mini satellites during orbit-raising suggest that SpaceX applies brightness mitigation when they reach a height of 357 km. The mean apparent magnitudes for objects below that height threshold is 2.68 while the mean for tho
Externí odkaz:
http://arxiv.org/abs/2405.12007
Autor:
Liming Li, X. Jiang, R. A. West, P. J. Gierasch, S. Perez-Hoyos, A. Sanchez-Lavega, L. N. Fletcher, J. J. Fortney, B. Knowles, C. C. Porco, K. H. Baines, P. M. Fry, A. Mallama, R. K. Achterberg, A. A. Simon, C. A. Nixon, G. S. Orton, U. A. Dyudina, S. P. Ewald, R. W. Schmude
Publikováno v:
Nature Communications, Vol 9, Iss 1, Pp 1-10 (2018)
Radiant energy budgets and internal heat play a key role in the evolution of planets. Here, the authors analyze data from the Cassini mission to show that Jupiter’s radiant energy and internal heat budgets are significantly larger than previous est
Externí odkaz:
https://doaj.org/article/92b1ada5213949ffbad5921127c4243c
Autor:
Mallama, Anthony, Cole, Richard E., Respler, Jay, Bassa, Cees, Harrington, Scott, Worley, Aaron
The illumination phase functions for Starlink Mini satellites are determined for times of twilight and darkness. Those functions are then evaluated to give apparent magnitudes over a grid of points across the sky and over a range of solar angles belo
Externí odkaz:
http://arxiv.org/abs/2401.01546
Autor:
Mallama, Anthony, Hornig, Andreas, Cole, Richard E., Harrington, Scott, Respler, Jay, Lee, Ron, Worley, Aaron
Photometric characteristics for all models of Starlink satellites launched to date are reviewed. The Original design that lacked brightness mitigation is the most luminous. SpaceX installed a sunshade on the VisorSat model which reduced its luminosit
Externí odkaz:
http://arxiv.org/abs/2309.14152
Autor:
Mallama, Anthony, Cole, Richard E., Harrington, Scott, Hornig, Andreas, Respler, Jay, Worley, Aaron, Lee, Ron
Starlink Generation 2 Mini satellites are fainter than Gen 1 spacecraft despite their larger size. The mean of apparent magnitudes for satellites in brightness mitigation mode is 7.06 +/- 0.10. When these magnitudes are adjusted to a uniform distance
Externí odkaz:
http://arxiv.org/abs/2306.06657